Watersheds
Title: What is a Watershed?
Essential Questions: How does the shape of the land affect the way water flows?
How does human activity affect the shape of a stream bed? Can the land around a
water body affect the quality of the water?
Engage:
Begin a preliminary discussion with the class by saying, “Let’s think about what happens
when it rains.” Student responses will, of course, vary greatly but highlight the mention
of water falling on different things and how it interacts with different surfaces. Begin to
set the stage for the definition and characteristics of a watershed by using questions
similar to these.
Does anyone know what causes a river to flow in a certain direction? Why does the
shape of a river channel develop the way it does? Can people affect the path of a
stream? Do you think the land around our rivers affects the quality of the water?
Use the first five slides of the presentation What is a Watershed?
Introduce the term watershed by asking students to separate the word into “water” and
“shed” (like a dog sheds fur or like a duck’s feathers shed water) and discuss what each
word means. Ask students what “sheds” water when it rains? (umbrellas, rooftops,
streets, or the land around a stream.)
Tell students that they will be using a model, which is a simplified representation of
something we could find in nature. Models help scientists express their current
understanding of a system and help them construct new knowledge.
Explore:
Materials: small wooden play blocks, aluminum foil, spray bottles, water, blue food
coloring, paper towels, pans
1. Students work in small groups to make a landform model.
2. Place six to eight of the small blocks into the bottom of the pan and orient them to
be as tall as possible.
3. Cover the blocks with a sheet of aluminum foil such that the surface is uneven
and there is at least one high point. The shape of the surface is not very critical
so students can feel free to make whatever shape they prefer.
4. Invite students to use their imaginations to pretend that the uneven surface they
are looking down on is an area of land. Explain that this is model that we are
using, much as scientist do when they are trying to understand the world.
5. Select students to describe the shape of the land that they are viewing, and
highlight the fact that there are high and low places which are separated by
peaks or ridges.
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Watersheds
6. Students use a spray bottle filled with blue colored water to simulate “rain” falling
on the landform. Spray bottles should be held about 12-18 inches from the pan.
7. Students observe and describe the behavior of the water when it falls on higher
and lower areas of the landform.
8. Highlight the fact that water will run in “streams” from higher to lower places and
that it will collect in lower places to form water bodies similar to lakes.
9. Direct students to notice some areas that are outlined by high points and form
“basins” in which water collects. Inform students that they have made a model of
a watershed (or perhaps several watersheds).
It is advisable to collect materials before moving on to the next part of the lesson.
Explain:
1. Distribute the handouts: Major Rivers of the U.S.and Kentucky Waterways and
Watersheds.
2. Begin the PowerPoint presentation What is a Watershed? Notes on the slides
provide a guide for the lesson. Students will be using the maps to determine
where the breaks between rivers occur – these are the watershed divides.
Divides separate watersheds from each other and form the outline for the shape
of a particular watershed. Refer back to the engage activity. Ask students to
recall that water ran from the high points of their model to the low points and
formed “basins”.
3. The US map has two main divides – the Western Continental Divide and the
Eastern Continental Divide. These separate the continental US into three major
watersheds – the Atlantic, Pacific and Gulf of Mexico. Major watersheds are also
called basins as in the Mississippi River Basin or Ohio River Basin.
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Watersheds
The Kentucky map is to help students become familiar with the major waterways in
Kentucky. Most of Kentucky’s watersheds end up in streams and rivers as our lakes
are all man-made and part of river systems (except for a few small lakes in far western
KY). The second part on the KY map is to sketch a watershed around the Kentucky
River and then the Green River. More can be done later if wanted.
The last map is Fayette County (your county map can be substituted). Again, the
purpose is to familiarize students with local streams and watersheds. Students can
locate their school on the map to see what watershed they are in.
Extend:
Introduce students to the idea that human activity within a watershed has an effect on
the flow and the quality of the water. Ask students to describe differences between the
urban and rural landscape that could have an effect on the watershed. Highlight such
factors as paved surfaces (parking lots and roads), agricultural practices (herbicides
and fertilizers), recreational areas (parks and golf courses), population density, etc.
Encourage students to brainstorm ideas about the effect of these factors on water
quality. Ask for suggestions about how these factors could be managed to reduce
harmful impacts on water quality.
The internet has multiple resources for watershed research. One site is the Kentucky
Watershed Viewer:
http://eppcmaps.ky.gov/website/watershed/viewer.htm This site uses maps to locate
watersheds all over Kentucky and contains tons of information. The easiest way to
locate is by county from a pull-up screen at the bottom of the map. All size watersheds
are presented on this site.
With a little effort a specific county map can be made from these maps by doing a ctrlalt-print screen and then pasting the picture into a word document and modifying the
picture to suit. ArcExplorer Online (http://explorer.arcgis.com/ ) could also be used in
much the same manner.
The Kentucky Geological Survey website also has much information on water in
Kentucky including PDF maps of the major river basins. Go to http://www.uky.edu/KGS/
and click on the water link for more.
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Watersheds
Notes from the PowerPoint presentation
1) What is a watershed?
2) Accept all responses. Then click to finish slide.
3) What is a watershed? Hill tops are called divides. Watershed is the land that drains water
into one place. Two divides are shown. Two divides separate three watersheds.
4) Map of US showing major rivers. Where do the rivers drain? (Atlantic, Pacific, Gulf of
Mexico)
Most of US drains to ???? (Gulf of Mexico) What River takes this water to the Gulf?
(Mississippi)
Look for the Watershed divides – called continental divides – student can come to screen and
try to point out the paths
Hypoxic Zone – low oxygen levels due to high runoff from fertilizers, pesticides, herbicides,
organic material – dead zone – growing. Stress the importance here. Everything that is done
in a very small watershed has an impact on the much larger picture.
5) Mississippi River Basin – blue
Ohio River Basin – red
Keep track of Kentucky (smiley face)
6) Keep track of KY – most of the state is in the Ohio River Basin (weather reports talk of the
Ohio River Valley – same thing)
7) All KY lakes are manmade (except for a few small ones in far western KY) – a dam was built
on a river to impound the water – usually for flood control, hydroelectric (1 and 2), recreation
Have students try to name the river before clicking to reveal each name. Keep track of specific
location too.
Note: Salt and Licking rivers get their names from the many salt licks used by animal herds and
pioneers to get their salt. Largest salt manufacturing site east of the Appalachians in late 1700’s
was in what is now Bullitt Co. on the Salt River.
Note: Cumberland source is in mountains of E. KY, flows south into TN and then west and north
back into KY – forms Lake Barkley
Tennessee River forms Kentucky Lake in western KY
8) Separating the rivers gives the approximate watershed or basin for each river. Note the next
slide for more formal results.
Can choose any river to do.
9) Major watersheds of Kentucky. Along the Ohio River there should be Ohio River watershed
areas (see the green areas above the Licking River watershed for example).
10) Do the same with the Fayette county streams. Stress that watersheds are getting smaller
and smaller. Also remind the students that what is done to a local watershed has impacts
downstream on other watersheds too (hypoxic zone in Gulf).
11) Basic watersheds of Fayette Co.
12) What is a watershed? The land that drains water into a stream, river or lake. It can be very
small or extremely large.
Tracing the watersheds for central KY could be: Town Branch, S. Elkhorn Creek, Elkhorn
Creek, Kentucky River, Ohio River, Mississippi River to the Gulf of Mexico.
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